Commit Graph
4 Commits
Author SHA1 Message Date
fd613edad0 Correct retention before enabling automatic deletion (#8)
* Correct retention before enabling automatic deletion

- Compute each retention tier's kept set independently from its own
  name range and union them, instead of carrying a single 'previous
  backup' comparison across tier boundaries - that carry-over was the
  actual cause of bug #32 (a coarser tier could evict a backup a finer
  tier, or the always-keep-latest rule, had already decided to retain)
- Group weekly retention by (ISO year, ISO week) instead of ISO week
  number alone, fixing bug #33 (same week number in different years,
  or late-December dates that belong to next year's ISO week 1, were
  treated as duplicates/collisions)
- Validate the computed retention plan (latest snapshot present, no
  phantom entries) before deleting anything
- Fix cli.py to run initiate_backup before cleanup_old_backups, and
  skip cleanup entirely if the backup raised - retention must only run
  once a new snapshot is durable and complete, and a failed backup must
  never trigger deletion of history
- Quarantine (rename) a deletion candidate before recursively removing
  it, reusing the already-hardened stale-staging-dir cleanup to finish
  the job if the process crashes mid-delete
- Remove both retention xfail markers (bugs #32, #33) now that the
  tests they guarded pass; update pre-existing tests whose expectations
  encoded the old bug (deleting the latest snapshot when it collided
  with the next-newest one in a coarser bucket)

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Address Copilot review: replace asserts with runtime checks, don't swallow quarantine-delete failures

- Retention-plan validation now raises BackupFailedError instead of
  using assert, which python -O would silently strip ahead of a
  destructive operation
- _quarantine_and_delete no longer passes ignore_errors=True to
  rmtree; a removal failure is now logged with the quarantine path so
  operators can find and retry it, instead of silently leaving a
  hidden directory consuming space

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

---------

Co-authored-by: Maxim Shulga <maxim.shulga@alludo.com>
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-03 22:47:43 +00:00
72a8fe2b59 Validate topology and destructive path boundaries (#7)
* Validate topology and destructive path boundaries

- Canonicalize sources/backups_dir and reject overlap in either direction
- Reject duplicate sources and destination basename collisions
- Reject non-normalized relative paths in nest_hardlink
- Give each backup repository a persistent identity, recorded in every
  snapshot's completion manifest
- Verify repo identity, directory type (no symlinks), containment, and
  device before any recursive snapshot/staging-dir deletion, refusing to
  cross mount points

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Address Copilot review: root-path check, symlink/TOCTOU-safe writes, legacy marker adoption

- _is_same_or_within: drop the redundant, root-mishandling startswith
  check; commonpath() alone is already component-aware
- _ensure_repo_id/_write_manifest: write via temp-file + atomic rename
  (O_NOFOLLOW, O_EXCL on the temp file) instead of open+write in place,
  so writes can never go through a pre-existing symlink and are never
  left half-written
- _verify_safe_to_delete: distinguish a legacy empty marker (pre-dates
  the manifest format, can only be a pre-migration artifact) from a
  non-empty-but-invalid one (corrupt or forged); adopt the former into
  the repository instead of refusing to delete it forever

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

---------

Co-authored-by: Maxim Shulga <maxim.shulga@alludo.com>
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-03 22:26:51 +00:00
a987180653 Replace PID-file process killing with a real fcntl.flock() lock (#6)
* Replace PID-file process killing with a real fcntl.flock() lock

set_backups_lock()/release_backups_lock() now use an exclusive
fcntl.flock() on the lock file's inode instead of trusting the PID
written inside it. The kernel releases the lock automatically on
normal exit, on any signal, and on a crash - no PID liveness check or
staleness heuristic is needed, and there is nothing left in this code
path that sends a signal to another process.

- The open file descriptor is held for the full operation in a
  module-level _held_locks map keyed by the backups directory, and
  release_backups_lock() only ever releases a descriptor this process
  itself acquired, never one it infers from the lock file's content.
- PID and start time are still written into the lock file, but purely
  as diagnostics for whoever reads it (e.g. in a warning log line);
  they play no role in acquisition or release decisions anymore.
- --force no longer sends SIGTERM/SIGKILL to the previous holder. It
  now blocks on the same flock() until that process releases the lock
  on its own (exit, signal, or crash all count).
- release_backups_lock() intentionally stops unlinking the lock file:
  since flock() locks an inode rather than a path, unlinking while
  another process is blocked opening the same path would let that
  process (or a third one) acquire an independent lock on a fresh
  inode at the same path, defeating mutual exclusion.

Rewrites TestBackupLock to match: a real second file descriptor with
its own flock() stands in for "another process" in the fast unit
tests, and a new subprocess-based test proves end-to-end that only one
process can hold the lock and that killing the holder with SIGKILL
frees it for the next acquirer without our code ever calling os.kill.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Address Copilot review feedback on flock-based lock

- Make the fcntl import optional (try/except ImportError -> None), so
  importing curateipsum.backup no longer crashes on Windows before
  cli.py's own "Not supported platform" check gets a chance to run.
- Guard set_backups_lock() against being called twice for a directory
  this process already holds: it now fails fast instead of silently
  overwriting the tracked fd in _held_locks, which would leak the
  original descriptor and leave the lock held even after
  release_backups_lock() closes only the newest one.
- Wrap the post-acquire metadata write (ftruncate/write/fsync) in a
  try/except: a failure there now releases the flock and closes the fd
  before returning False, instead of leaving the lock held with
  no caller aware of it.
- Cap _read_lock_metadata()'s read and strip newlines before logging,
  so a stale or forged lock file can't inject bogus log lines or force
  an unbounded read.

Adds a regression test for the double-acquire guard.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

---------

Co-authored-by: Maxim Shulga <maxim.shulga@alludo.com>
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-03 22:00:21 +00:00
a48eaf8117 Make snapshot creation transactional (#5)
* Make snapshot creation transactional

Build each snapshot in a private .incomplete-<name> staging directory
instead of mutating the final backup path directly. Any failure while
building the snapshot (hardlink failure, rsync error, or a single
Actions.ERROR entry) is now fatal: the staging directory is discarded
and BackupFailedError is raised, so a failed or interrupted backup can
never silently look like a success.

On success, the completion marker is written and the directory fsync'd
before an atomic os.rename() into the final snapshot name, so a crash
can never leave a partially-populated directory under a real snapshot
name.

Also:
- cleanup_stale_staging_dirs() removes abandoned staging directories
  left by a crashed run before a new backup starts.
- _reserve_snapshot_name() avoids same-second snapshot name collisions.
- cli.py releases the backup lock in finally and returns a nonzero
  exit code when BackupFailedError is raised.

Updates the error-recovery tests that previously asserted failures
were swallowed silently to assert BackupFailedError is raised instead,
matching the new fail-loud contract.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* Address Copilot review feedback on transactional snapshots

- Remove unused uuid import.
- _reserve_snapshot_name() also checks for a collision with an existing
  .incomplete-<name> staging directory, not just the final snapshot
  name.
- _fsync_dir() opens with O_DIRECTORY where available.
- Fsync the completion marker file itself, and fsync the parent
  backups_dir after the rename, so the marker and the rename survive a
  crash/power loss.
- Re-raise an already-BackupFailedError unchanged (preserving its
  traceback) instead of wrapping it in a new instance; only
  fs.BackupCreationError gets wrapped.
- Wrap the initial os.mkdir(staging.path) failure in BackupFailedError
  so every failure path uses the documented exception.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

---------

Co-authored-by: Maxim Shulga <maxim.shulga@alludo.com>
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
2026-08-03 21:30:39 +00:00